Bio-optical sensors detect photo-emissive chemical reactions between an analyte and a reagent. Improved bio-optical sensors have a number of different reagents to enable them to detect the presence/concentration of several analytes. During the manufacture of such sensors, it is necessary to locate and separate the reagents, and during their operation, it is necessary to guide the sample containing the analyte over the sensor sites.
The sites should be mechanically isolated. Suitable structures may be patterned and etch, either on the silicon of the sensor surface or by making trenches in the silicon itself. However, these methods currently require special technology, processing and equipment which add to the manufacturing cost.
When forming a structure on the surface of the sensor, materials such as polyimide are typically used because they provide good patterning and etching properties. While found in a research laboratory, these chemicals are not usually found in a production environment. The introduction of these materials requires a modification to normal production processes.